Coffee machine with dynamic flow and temperature control

ABSTRACT

A coffee machine is provided. The coffee machine may include a water line configured to supply water, a pump configured to pressurize the water, a first in-line heating element configured to heat the water to an intermediate temperature, a second in-line heating element configured to heat the water from the intermediate temperature to a temperature set point during an extraction process, and one or more electronic control modules configured to receive brewing settings, the brewing settings including the at least one temperature set point, estimate, based partially on the intermediate temperature, a flow rate of the water through the first in-line heating element, and adjust, based at least partially on the estimated flow rate, a power provided to the second in-line heating element.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation-in-part of U.S. patent applicationSer. No. 17/084,664, entitled “Coffee Machine with Dynamic Flow andTemperature Control,” filed on Oct. 30, 2020. The subject matter of theaforementioned application is incorporated herein by reference in itsentirety for all purposes.

TECHNICAL FIELD

The present disclosure relates generally to coffee machines and, moreparticularly, to coffee machines with dynamic flow and temperaturecontrol.

BACKGROUND

Semi-automatic coffee machines, such as the Faema E61, La MarzoccoLinea, Nuova Simonelli Aurelia, and Astoria Sabrina, traditionallydelivered water to a brewing chamber at a fixed pressure, for example,of nine bars. Coffee machines, as originally developed andcommercialized, contained a boiler that heated water and afixed-pressure pump that forced heated water out of the boiler into abrewing chamber that contained ground coffee. The temperature of thebrewing water was controlled by a thermostat (“bang-bang”) or apressurestat controller which maintained a water temperature to within5-10° C. of a set point. However, coffee flavor can be overly sensitiveto the temperature of brewing water and require lower temperaturevariations. Therefore, using a boiler with a temperature range of 5-10degrees can result in an inferior brew. Additionally, flavor and tasteof a coffee beverage depends on a combination of parameters such as acoffee amount, water amount, grind settings, beverage volume, and waterpressure.

Recently, the use of a Proportional Integral Derivative (“PID”)controller has emerged as a standard for temperature control for brewingdevices. A PID controller can be integrated within traditional machinesvia aftermarket kits or in revised designs that replace the (oftenmechanical) thermostat/pressurestat with an electrical circuit tomaintain temperature typically within 0.5-1.0° C. of a set point. Thisincreased control has yielded improvements in consistency and flavor andhave become a de facto standard.

In other applications, various in-line or on-demand heaters are used toeliminate the need for reservoirs of heated water whose temperature mustbe maintained even when water is not being drawn by the device. Thismakes it possible for devices with high throughput to maintain a smallerfootprint and to eliminate the need to maintain heated reservoirs.Advancements in temperature control have made this possible fornon-pressurized coffee brewing (“drip” coffee) and have beencommercialized by the Luminaire Bravo and other existing coffee makers.

In-line heaters cannot practically be used for fixed-pressure systemsbecause the flow rate of water is unknown and unpredictable andcontemporary commoditized flow measurement devices do not provide thenecessary precision to dynamically heat brewing water to the tolerancesrequired for high-grade espresso.

Traditional coffee machines have boilers. A substantial cost in themanufacture, footprint, and maintenance of the traditional coffeemachines is due to the requirement of a boiler that can withstand boththe temperature and pressure of brewing water.

Traditional coffee machines have a pump that provides fixed pressure.However, because the pressure is fixed, the flow rate depends on theresistance of the coffee. Thus, if coffee provides considerableresistance, the flow rate decreases. Vice versa, if the coffee provideslittle resistance, the flow rate increases. Thus, maintaining constantflow rate or even predicting the flow rate in the traditional coffeemachines is difficult. Furthermore, to maintain the temperature,traditional coffee machines use large boilers. However, with largeboilers, the temperature of water cannot be dynamically varied duringthe extraction process because it takes a long time and large amounts ofenergy to change the temperature of water in large water boilers by justa few degrees, whereas the extraction typically takes a short time.

One way to control the flow rate in a traditional coffee machine is tovary the coffee puck, for example, by changing the grind, dose, or forceused in tamping. This approach to controlling the flow rate is indirectand difficult to implement even with high degrees of skill.

Furthermore, temperature and pressure of water in a boiler tends toincrease the chemical activity of the water, which can result in rustand lime depositions inside the boiler.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

According to one example embodiment, a coffee machine is provided. Thecoffee machine may include at least one water line configured to supplywater and at least one pump configured to pressurize the water. Thecoffee machine may include a first in-line heating element and a secondin-line heating element. The first in-line heating element can beconfigured to heat the water to an intermediate temperature. The secondin-line heating element can be configured to heat the water from theintermediate temperature to at least one temperature set point during anextraction process. The coffee machine may include one or moreelectronic control modules. The electronic control modules can beconfigured to receive brewing settings. The brewing settings may includethe temperature set point. The electronic control modules can beconfigured to estimate, based at least partially on the intermediatetemperature, a flow rate of the water through the first in-line heatingelement. The electronic control modules can be configured to adjust,based at least partially on the estimated flow rate, a power provided tothe second in-line heating element.

A difference between an ambient temperature and the intermediatetemperature can be larger than a difference between the intermediatetemperature and the at least one temperature set point. The differencebetween an ambient temperature and the intermediate temperature can beset a predetermined percentage of the difference between the ambienttemperature and the temperature set point.

The electronic control modules can be configured to control, based atleast partially on the flow rate of the water through the first in-lineheating element, pressure of the at least one pump.

The coffee machine may include a first temperature sensor, a secondtemperature sensor, and a third temperature sensor. The firsttemperature sensor can be disposed between the at least one pump and thefirst in-line heating element and configured to sense a firsttemperature of the water. The second temperature sensor can be disposedbetween the first in-line heating element and the second in-line heatingelement and configured to sense the intermediate temperature of thewater. The third temperature sensor can be disposed between the secondin-line heating element and a brewing chamber and configured to sense asecond temperature of the water.

The electronic control modules can be configured to control powerprovided to the first in-line heating element based on the followingvariables: an ambient temperature, the first temperature of the water,the intermediate temperature of the water, the temperature set point,and parameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element.

The electronic control modules can be configured to estimate the flowrate of water through the first in-line heating element based on thefollowing variables: an ambient temperature, the first temperature ofthe water, the second temperature of the water, the temperature setpoint, and parameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element.

The electronic control modules can be configured to monitor, during apredetermined period, the following variables: an ambient temperature,the first temperature of the water, the intermediate temperature of thewater, the second temperature of the water, flow rate of the waterthrough the first in-line heating element. The electronic controlmodules can be configured to update, based on the monitored variables,parameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element.

The pump may include one of the following: a syringe pump, a vane pump,a rotary vane pump, and a gear pump. The line can be configured toconnect one or more of the following: an inlet to the at least pump, theat least one pump to the first in-line heating element, the firstin-line heating element to the first in-line heating element, and thesecond heating element to a brewing chamber. The brewing chamber mayinclude a portafilter configured to hold coffee and a group headconfigured to receive the portafilter.

The temperature set point vary during the extraction process accordingto the brewing settings. The brewing settings can be provided by anoperator or predetermined based on a brewing profile. The brewingprofile may include pre-programmed set points for preparing one or moreof the following beverages: espresso, drip coffee, and cold brew.

According to another embodiment of the present disclosure, a method forbrewing a coffee beverage is provided. The method may include receiving,by one or more electronic control modules, brewing settings. The brewingsettings may include at least one temperature set point. The method mayinclude supplying, by at least one water line, water. The method mayinclude pressurizing, by at least one pump, the water. The method mayinclude heating, by a first in-line heating element, the water to anintermediate temperature. The method may include heating, by a secondin-line heating element, the water from the intermediate temperature toat least one temperature set point during an extraction process. Themethod may include estimating, by the electronic control modules andbased partially on the intermediate temperature, a flow rate of thewater through the first in-line heating element. The method may includeadjusting, by the electronic control modules and, based at leastpartially on the estimated flow rate, power provided to the secondin-line heating element.

Additional objects, advantages, and novel features will be set forth inpart in the detailed description section of this disclosure, whichfollows, and in part will become apparent to those skilled in the artupon examination of this specification and the accompanying drawings ormay be learned by production or operation of the example embodiments.The objects and advantages of the concepts may be realized and attainedby means of the methodologies, instrumentalities, and combinationsparticularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and not limitation in thefigures of the accompanying drawings, in which like references indicatesimilar elements.

FIG. 1 is a mechanical schematic of a conventional espresso machine.

FIG. 2 is a mechanical schematic showing a high-level structure of acoffee machine, according to an example embodiment.

FIG. 3 shows a mechanical schematic showing a structure of a coffeemachine, according to an example embodiment.

FIG. 4 is a schematic showing diagram showing a detailed structure of acoffee machine, according to an example embodiment.

FIG. 5 shows a mechanical diagram of a syringe pump assembly, accordingto an example embodiment.

FIG. 6A is an exploded view of a portafilter used in a coffee machine,according to an example embodiment.

FIG. 6B is an exploded view of a slide-in portafilter used in a coffeemachine, according to an example embodiment.

FIG. 7 shows a diagram illustrating flow characteristics, according toan example embodiment.

FIGS. 8A and 8B illustrate controlling temperature via a feedback loopin conventional coffee machines.

FIGS. 8C and 8D illustrate controlling temperature via a feedback loopin a coffee machine, according to an example embodiment.

FIG. 9 is a flow chart of an example method for manufacturing a coffeemachine, according to some example embodiments.

FIG. 10 is a schematic diagram showing a group head used in a coffeemachine, according to an example embodiment.

FIG. 11 shows a user interface associated with a coffee machine,according to an example embodiment.

FIG. 12 shows a computing system that can be used in association with acoffee machine, according to an example embodiment.

FIG. 13 is a block diagram showing a high-level structure of a coffeemachine, according to another example embodiment.

FIG. 14 is a schematic showing functionalities of electronic controlmodules of a coffee machine, according to an example embodiment.

FIG. 15 is a flow chart showing a method for brewing coffee beverages,according to some example embodiments.

DETAILED DESCRIPTION

The following detailed description includes references to theaccompanying drawings, which form a part of the detailed description.The drawings show illustrations in accordance with example embodiments.These example embodiments, which are also referred to herein as“examples,” are described in enough detail to enable those skilled inthe art to practice the present subject matter. The embodiments can becombined, other embodiments can be utilized, or structural, logical, andelectrical changes can be made without departing from the scope of whatis claimed. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope is defined by the appendedclaims and their equivalents.

The present disclosure provides a coffee machine and method formanufacturing the coffee machine. The coffee machine may include aflow-controlled and temperature-controlled coffee machine. The coffeemachine can provide superior temperature and flow control to an operator(e.g., a barista) in a smaller footprint than traditional coffeemachines. The coffee machine includes at least one syringe pump (or aplurality of redundant syringe pumps in some embodiments) to control thepressure of water flow and an in-line heater (also referred herein to anin-line heating element) to rapidly change the temperature of the water.The in-line heater may include one or more heating elements covered witha special type of a vessel chamber that has anti-corrosion properties.The in-line heater provides indirect heating of fluid. Specifically, thefluid is circulated through a closed loop around the heating elementsuntil the fluid reaches the correct temperature.

The in-line heater can be located down the stream from the syringe pumpand, therefore, is not required to maintain pressure as boilers oftraditional coffee machines. Accordingly, the in-line heater can beinexpensively made of materials that do not react with water and do notproduce sediments. The in-line heater allows physical separation of thesyringe pump from the point of delivery without taking prohibitivemeasures to insulate a water line. A sufficiently powerful in-lineheater is able to heat brewing water from inlet temperature to thedesired brewing temperature and obviates the need for a heatedreservoir. This allows baristas to append a full range of variables in asingle device: a flow profile, temperature profile, ground geometry andinput mass, and a filter type and geometry such that the coffee machinecan achieve a total continuum between espresso, drip coffee, andcold-brew coffee, as well as other types of coffee beverages.

The coffee machine allows controlling the flow rate directly by using asyringe pump to change pressure as needed depending on predeterminedcriteria. The flow rate can be controlled to allow the in-line heater tomaintain a certain temperature and, thus, the desired temperature can bemaintained by using a small heating element instead of a large boiler.This direct control of the flow rate allows maintaining a desired andconstant temperature control using the in-line heating element and noboiler.

Thus, instead of resistance of coffee dictating the flow rate intraditional coffee machines, the syringe pump can be used to maintainthe flow rate. Specifically, to maintain the flow rate, the syringe pumpcan have an electric motor configured to provide the required flow rate.For example, one turn of the electric motor may push through apredetermined volume of water, e.g., a predetermined number ofmilliliters of water per second. The in-line heater can dictate thetemperature of the water as needed during the extraction process.

Another advantage of the coffee machine is fast and dynamic variation ofthe temperature during the extraction process that can be controlledaccording to setting provided by an operator. For example, the coffeemachine can start the process with one temperature, and then increase ordecrease the temperature as desired.

To avoid unnatural twisting motion required to perform by a baristawhile making espresso, the traditional E61 group head can be replacedwith a forward-sliding group head such that the portafilter can be movedalong a track just under the group head. A contact switch can beinstalled at the end of the track. When the barista releases the grouphead, the portafilter can be weighed, the weight of the portafilter(which is stored in a memory of the coffee machine) can be subtracted,yielding the weight of the grounds. The group head can then drive theportafilter up, thereby sealing a gasket and commencing the extractionaccording to a preprogrammed temperature and flow profile, using theweight of the grinds as an input.

A programming interface can be designed to optimize experience of thebarista. In some embodiments, the programming interface can include alearning mode to be executed at the beginning of the day or when a newbean is used such that a particular extraction can be repeatedautomatically later. In some embodiments, a barista is able to make fineadjustments (increase or decrease extraction or increase or decreasestrength) to the learned mode.

Additionally, the programming interface can provide a fine adjustmentmode along two dimensions (increase or decrease extraction, increase ordecrease strength) enabling an operator to easily make minor adjustmentsto the brewing profile.

The coffee machine allows achieving a truly constant temperature orchanging the temperature during the course of extraction according to apredetermined brewing profile. Using the coffee machine, the extractioncan be started, for example, at 93 degrees Celsius, raised to 98 degreesCelsius for 10 seconds, and then brought down to 85 degrees Celsius forthe last 10 seconds. Lower temperatures may be needed for a “cold” brew.

Thus, the coffee machine is smaller, less expensive to build, and lessexpensive to maintain and gives the barista more control over theextraction process than a traditional machine.

In some embodiments, the coffee machine may have a pressure sensorconfigured to measure the pressure of water. An electronic controlmodule can receive, via a feedback loop, the pressure measured by thepressure sensor. Based on the measured pressure, the electronic controlmodule may adjust the pressure by using the syringe pump, e.g., when apredetermined pressure is needed for preparation of a specific type ofcoffee beverage (such as nine bars for espresso). Additionally, thetemperature can be adjusted based on the data received from atemperature sensor.

An example coffee machine may consist of an inlet, a syringe pump, anin-line heating element, a group head, and water lines connecting theinlet to the syringe pump, the syringe pump to the in-line heatingelement, and the in-line heating element to the group head. The coffeemachine provides an improved control over brewing parameters tobaristas, where the improved output quality flow rate is a primaryfactor in brewing characteristics and water pressure is secondary to theflow rate in controlling brewing to provide accurately controlled,non-constant flow rate and pressure (optionally, if desired) by directlycontrolling the flow rate of brewing water for accurate in-line heating.

According to one embodiment of the present disclosure, a coffee machinemay include a brewing chamber, at least one water line configured tosupply water, at least one pump configured to pressurize the water, afirst in-line heating element, and a second in-line heating element. Thefirst in-line heating element can be configured to heat the water to anintermediate temperature. The second in-line heating element can beconfigured to heat the water from the intermediate temperature to atleast one temperature set point during an extraction process. The coffeemachine may include a first temperature sensor, a second temperaturesensor, and a third temperature sensor. The first temperature sensor canbe disposed between the at least one pump and the first in-line heatingelement and configured to sense a first temperature of the water. Thesecond temperature sensor can be disposed between the first in-lineheating element and the second in-line heating element and configured tosense the intermediate temperature of the water. The third temperaturesensor can be disposed between the second in-line heating element andthe brewing chamber and configured to sense a second temperature of thewater. The coffee machine may include one or more electronic controlmodules configured to receive brewing settings. The brewing settingsincluding the temperature set point. The one or more electronic controlmodules can estimate a flow rate of the water through the first in-lineheating element based on an ambient temperature, the first temperatureof the water, the second temperature of the water, the temperature setpoint, and parameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element. The one or more electronic control modules canadjust a power provided to the second in-line heating element based onthe ambient temperature, the intermediate temperature of the water, thesecond temperature of the water, the temperature set point, andparameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element.

Referring now to the drawings, FIG. 1 shows a mechanical schematic of aconventional espresso machine 100. The espresso machine 100 has an inlet105 (connected to a water source, such as a reservoir or a water line(not shown)), a pump 110 as a fixed-pressure source (such as a manualpiston, a vibration pump, a rotary pump, or gear pump), a boiler 115, acoffee puck 120, and an outlet 125. The pump 110 is used to force waterfrom the inlet 105 into the boiler 115, which heats the water. Theoutlet of the boiler 115 is connected (via a group head and aportafilter (not shown) to a coffee puck 120. The coffee puck 120 is acompressed disc of grounds placed into the portafilter and insertedtogether with the portafilter into the group head of the espressomachine 100. The water is pumped through the coffee puck 120 to produceespresso shown as coffee 130 at the outlet 125 of the espresso machine100.

FIG. 2 shows a mechanical schematic of a high-level structure of acoffee machine 200 of the present disclosure, according to an exampleembodiment. The coffee machine 200 has a water inlet shown as an inlet205, a water reservoir shown as a reservoir 210, a pump 215 placeddownstream the reservoir 210, a mechanical resistor of water flow in theform of a compressed puck of ground coffee shown as a coffee puck 220,and an outlet 225. In an example embodiment, the reservoir 210 may beconfigured to heat the water. The pump 215 may include afixed-displacement pump. The water passes from the inlet 205 into thereservoir 210 and then is pumped by the pump 215 from the reservoir 210to the coffee puck 220. The water is pumped through the coffee puck 220to produce espresso shown as coffee 230 at the outlet 225 of the coffeemachine 200.

FIG. 3 shows a mechanical schematic showing a more detailed structure ofa coffee machine 300 of the present disclosure, according to an exampleembodiment. The coffee machine 300 may have an in-line heating element305 placed after the pump 215. One or more temperature sensors 310 maybe connected to a water line 315 (e.g., upstream and downstream thein-line heating element 305) enabling to deliver water that is partiallyor wholly heated on demand. The one or more temperature sensors 310 mayinclude one or more thermocouples.

In an example embodiment, the reservoir 210 can be configured to heat orpre-heat the water. The extent to which heating is done by the reservoir210 and the in-line heating element 305 may be varied. In some exampleembodiment, providing more heating by the reservoir 210 may result ingreater temperature stability, whereas providing more heating by thein-line heating element 305 may result in a wider range of achievabletemperature profiles.

FIG. 4 is a schematic showing diagram a coffee machine 400 of thepresent disclosure, according to an example embodiment. The coffeemachine 400 may include an inlet 205, optionally a reservoir 210, anelectronic control module 405, a portafilter 410 configured to holdcoffee, a group head 415 configured to receive the portafilter 410, atleast one water line 420 configured to supply water, a pressure sensor425 (optional) configured to sense a pressure of the water, at least onepump such as at least one syringe pump 430, an in-line heating element435, at least one feedback loop shown as a feedback loop 440 and afeedback loop 445, and an outlet 225. The coffee machine 400 may furtherinclude at least one temperature sensor 450. The coffee machine 400 mayfurther include check valves 455. In some embodiments, the coffeemachine 400 may include no reservoir 210 with the water being providedfrom the input 205 to the at least one water line 420 (e.g., in a formof a tube) and then to other components of the coffee machine 400.

The at least one water line 420 may connect the inlet 205 to the atleast one syringe pump 430, the at least one syringe pump 430 to thein-line heating element 435, and the in-line heating element 435 to thegroup head 415.

The electronic control module 405 may be configured to receive brewingsettings. The brewing settings may include at least one flow set pointand at least one temperature set point. The brewing settings may beprovided by an operator of the coffee machine 400. In other exampleembodiments, the brewing settings may be predetermined based on abrewing profile. The brewing profile may include pre-programmed setpoints for preparing one or more of the following beverages: espresso(with the hot water being forced through compressed grounds and amechanical filter, the pressure further increasing the rate ofextraction and reducing the brewing time to under a minute), drip coffee(ground coffee combined with hot water, brewed coffee is mechanicallyseparated from the depleted grounds after a few minutes, with thetemperature increasing the rate of extraction and possible damage tocompounds found in coffee), cold brew (with ground coffee being combinedwith cold water, the mixture held at a low temperature for severalhours, then brewed coffee mechanically separated from the depletedgrounds), and other beverages.

The electronic control module 405 may provide setting, such as the atleast one flow set point, to the at least one syringe pump 430. Theleast one syringe pump 430 may be an infusion device configured togradually administer specific amounts of fluids. The at least onesyringe pump 430 may receive the at least one flow set point from theelectronic control module 405 and pressurize the water to attain the atleast one flow set point. In an example embodiment, the at least oneflow set point may be selected to maintain the at least one temperatureset point.

The at least one syringe pump 430 may pressurize the water based onpredetermined criteria. Specifically, the at least one syringe pump 430may have an electric motor 470 configured to provide the pressure ofwater selected based on predetermined criteria. The predeterminedcriteria may include, for example, the pressure needed for preparingspecific types of coffee beverages. In an example embodiment, theelectric motor 470 may have parameters, according to which, one turn ofthe electric motor 470 provides a pressure that results in apredetermined flow rate (e.g., a predetermined number of milliliters ofwater per second).

The electronic control module 405 may provide setting to the in-lineheating element 435. The in-line heating element 435 may be configuredto heat water on-demand. The in-line heating element 435 may be locateddown the stream from the at least one syringe pump 430. In an exampleembodiment, the electronic control module may include a PID controllerconfigured to control the at least one temperature set point within arange of 0.5° C. to 1.0° C.

Conventional fixed-pressure coffee machines fail to achieve stabletemperature control because a hydraulic resistor (the coffee puck) canbe unstable, causing the flow rate to vary unpredictably over the courseof extraction. The coffee machine 400 described herein is a fixed-flowsystem. Since the flow is directly controlled, the amount of energyneeded to achieve the desired temperature can be computed as follows:

I∝(T ₀ −T _(i))·Φ,

where I is the in-line heater current, T₀ and T_(i) are the currenttemperature and desired temperature, respectively, and Φ is the rate ofwater flow.

With the in-line heater, the pump can be physically separated from thepoint of delivery without taking prohibitive measures to insulate thewater line. A sufficiently powerful in-line heater that is able to heatwater from inlet temperature to the desired brewing temperature mayobviate the need for a heated reservoir.

Improved temperature stability and redundancy can be achieved inmultiple stages. Subsequent stages could be able to use the change intemperature from earlier stages to improve the estimation of the flowrate. For example:

${I_{1} \propto {0.8{\left( {T_{0} - T_{i}} \right) \cdot \Phi}}},{I_{2} \propto {\frac{T_{0} - T_{m}}{T_{0} - T_{i}}I_{1}}},$

where I₁ and I₂ are the in-line heater currents of the first- andsecond-stage in-line heaters, respectively, T_(i) is the temperaturebefore the first stage, T_(m) is the temperature in between the stages,and T_(o) is the desired output temperature.

Finally, this configuration enables the coffee machine 400 to providetemperature profiling, namely the direct dynamic temperature control toprovide extraction control beyond any traditional coffee machine.

The in-line heating element 435 may receive the at least one temperatureset point from the electronic control module 405 and may controltemperature of the water according to the at least one temperature setpoint during an extraction process. Specifically, the in-line heatingelement 435 may be configured to change the at least one temperature setpoint based on the brewing settings.

During the operation of the coffee machine 400, the feedback loop 445may provide the temperature measured by the temperature sensor 450 tothe electronic control module 405. Upon receiving the values oftemperature via the feedback loop 445, the electronic control module 405may selectively adjust the temperature based on the brewing settings.Thus, the at least one flow rate set point and the at least onetemperature set point can vary during the extraction process accordingto the brewing settings.

Optionally, during the operation of the coffee machine 400, the feedbackloop 440 may be configured to provide the pressure measured by thepressure sensor 425 to the electronic control module 405. Upon receivingthe pressure values via the feedback loop 440, the electronic controlmodule 405 may selectively adjust the pressure based on the brewingsettings.

The feedback loop 440 and the feedback loop 445 may include an openloop, a linear closed-loop, and a non-linear closed-loop.

The at least one syringe pump 430 may push out the fluid via a piston465 (acting as a syringe) to obtain a predetermined volume depending onthe size of the piston 465. In an example embodiment, the at least onesyringe pump 430 may include a plurality of redundant syringe pumps 460forming a reciprocating syringe pump assembly to achieve a continuousflow. Check valves 455 can be placed at the inputs and outputs of eachof the syringe pumps 460. Each syringe pump 460 may have a piston 465and an electric motor 470 arranged to cause linear motion of the piston465. Additionally, a linear encoder for the at least syringe pump 430can provide an additional level of precision for the syringe pump 430.

In an example embodiment, the electronic control module 405 may includea learning mode configured to learn a brewing profile executed manuallyby an operator. Specifically, the operator may set the temperature andpressure manually. The coffee machine 400 may further include a memoryunit (not shown) that stores the brewing profile learned by theelectronic control module 405 based on temperature and pressure valuesreceived from the operator.

In further example embodiments, the electronic control module 405 may beconnected to a data network and receive a brewing profile from externalsources. The external sources may include database records stored on thedata network, other coffee machines connected to the data network, andother network resources. A plurality of coffee machines may storelearned profiles in a shared memory in the database. For example, theelectronic control module 405 of the coffee machine 400 may receivebrewing profiles learned by other coffee machines and stored in thedatabase.

Thus, in the coffee machine 400, the flow can be directly controlled bythe actuation of the syringe pump. Furthermore, the buildup of scale inthe heater can be mitigated by the use of plastic components and theabsence of stagnant, pressurized, heated water. The water can be safelyconditioned to avoid rust since the active ions have no iron-bearingcomponents to attack. Thus, in contrast to the conventional coffeemachines, the water reservoir is not required to maintain pressure, suchthat the coffee machine 400 can be compact and inexpensive tomanufacture and maintain.

The group head is traditionally heated by drawing energy from a boilerby conduction (often the group head and boiler are a single component),by circulating boiler water through the group head (a “saturatedgroup”), or by separately heating the group head via resistive heating.In the coffee machine 400, the group head may be also cooled to provideaggressive two-sided control. Cooling can be achieved via a fan orcirculating lower-temperature fluid over or through the group head. Thegroup head can also incorporate or be encased in a material thatundergoes a phase change at the desired temperature, which could provideadditional thermal inertia by stabilizing the temperature of the grouphead at the temperature of the phase change of the material.

By directly heating the group head and removing the need for a vesselthat contains a large quantity of water at high temperature and pressure(i.e., the boiler), a greater degree of modularity can be provided bythe coffee machine 400 without sacrificing the cost or efficiency.

In an example embodiment, a current can be measured at the pump andpressure can be measured before the group head for safety reasons. Asignal indicating how much force the pump is applying to achieve theflow rate may be provided to the electronic control module 405. Thecoffee machine 400 can have light emitting diodes to indicate unsafeconditions at any component. The electronic control module canincorporate information from sensors via an artificial intelligencenetwork to detect conditions requiring service and to automatically takeadvantage of redundant components to increase the margin of safety,quickly detect gasket or motor failures and dynamicallyself-reconfigure, and report dangerous conditions to the operator.

In example embodiment, the coffee machine 400 may have one or moreadditional sensors configured to measure one or more of the following:ambient air temperature, inlet water temperature, reservoir outlet watertemperature, pump current, and so forth. The sensors may further includea pump encoder (i.e., a linear encoder for a syringe pump, a rotaryencoder for a rotary pump), a group head contact switch, a group headscale, a group head temperature sensor, an auto-lock current/forcesensor, an under-group head scale, pre-group head temperature sensor(s),a pre-group head pressure gauge, and so forth.

In example embodiment, the coffee machine 400 may have one or moreactuators, such as a reservoir input solenoid/valve, a reservoirtemperature actuator, a reservoir selection solenoid, a group headtemperature actuator, a group head auto-lock, a basket valve, a basketstir-bar, a dry group head solenoid, and so forth.

FIG. 5 shows a mechanical diagram of a syringe pump assembly 500. Thepump assembly 500 may have hydraulic interfaces 505 and a manifoldassembly 510 for pistons 465.

Referring again to FIG. 4, in an example embodiment, the in-line heatingelement 435 may be provided in the form of a multistage in-line heatingelement and may include more than one in-line heater 475 and more thanone temperature sensor 450. The temperature sensors 450 may be presentbefore and after each in-line heater 475. The in-line heating element435 may precisely control the temperature of the group head 415. In anexample embodiment, the in-line heating element 435 may be made ofmaterials selected to be non-reactive with the water to avoid sedimentformation.

An over-pressure valve 480 can be placed to guarantee that the pressuredoes not exceed the mechanical specifications of the components of thecoffee machine 400. The coffee machine 400 may further include anelectrically actuated drain 485 to partially dry the coffee puck 220after the extraction and prior to the pressure release. In an exampleembodiment, the drain 485 may include a manual valve to relieve pressureand draw water at the end of an extraction.

Additionally, a group head heater 490 and a temperature sensor 490 maybe provided in the group head 415. The group head heater 490 may heatthe group head 415 in order to precisely control the temperature of thegroup head 415 based on the measurements of the temperature sensor 490placed into the group head 415.

FIG. 6A is an exploded view of a portafilter 600 used in the coffeemachine, according to another embodiment. The portafilter 600 mayinclude a body 602 and a bayonet ring 605, which may create a mechanismto convert a rotation 615 of the body 602 of the portafilter 600 aboutan axis 620 into a linear movement 625 into a gasket 630, therebycreating the pressure seal needed for brewing. The water can bedelivered through a dispersion screw 635 and spread over the surface ofthe body 602 of the portafilter 600 via a screen 640.

FIG. 6B is an exploded view of a slide-in portafilter 650 used in thecoffee machine, according to another embodiment. The body 602 of theportafilter 650 can be moved in a direction 670 along a track 655 undera group head, which is composed of the gasket 630, the screen 640, andthe dispersion screw 635. In this embodiment, the group head is aforward-sliding group head configured to receive the body 602 of theportafilter 650 being moved along the track 655. A contact switch 660and a lift coupler 665 may be provided at the end of the track 655 tointerface the body 602 of the portafilter 650 to the group head andauto-lock the body 602 with the group head. The contact switch 660 maybe embedded into the group head to detect when the body 602 of theportafilter 650 is present to trigger auto-lock and/or to beginextraction. Additionally, a scale may be incorporated within the grouphead to measure the weight of the ground coffee. When an operatorreleases the group head, the portafilter 650 is weighed, the weight ofthe portafilter 650 (which is stored in a memory unit of the coffeemachine) is subtracted, and the weight of the ground coffee iscalculated. The portafilter 650 is then driven up, thereby sealing thegasket 630 and commencing the extraction according to preprogrammedtemperature and flow set points profile using the weight of the groundcoffee as an input. Therefore, the group head automatically maneuversthe portafilter 650 to seal the gasket 630 before extraction begins andto release the gasket 630 after the extraction completes.

FIG. 7 shows a diagram 700 illustrating flow characteristics of aconventional coffee machine. In the conventional coffee machine, thepressure 705 is a primary variable used to control the flow rate 710. Inview of this, a fixed-pressure pump is usually provided in theconventional coffee machine. The temperature 715 is usually maintainedat a predetermined range by a boiler.

FIG. 7 also shows a diagram 750 illustrating flow characteristics of acoffee machine of the present disclosure. The flow rate 760 is primaryvariable, while the pressure 755 is a secondary variable. Thus, afixed-flow pump is provided to control the flow rate 760. Additionally,as the flow rate 760 is controlled, the amount of water that is passingthrough the in-line heating element is known. Accordingly, a precisecontrol of the temperature 765 can be provided by the in-line heatingelement based on the calculated amount of water.

FIGS. 8A and 8B illustrate controlling temperature via a feedback loopin conventional coffee machines. Traditionally, the temperature of aboiler is controlled via a “bang-bang” controller: a heating coil of theboiler is switched on when the sensed temperature falls below a certainthreshold T₁ and is switched off when the sensed temperature rises aboveanother threshold T₂. The choice of the difference between the twothresholds T₂−T₁ is a tradeoff between improved temperature stabilityand improved energy consumption and heating coil life. Typical valuesare in the 5-10° C. range. See FIG. 8B showing a temperature profileprovided by conventional coffee machines.

FIGS. 8C and 8D illustrate controlling temperature via a feedback loopin the coffee machine of the present disclosure. In espressopreparation, the flavor is sensitive to the temperature of brewingwater. Thus, the PID controller and a feedback loop can be used toefficiently control the temperature of the water in the in-line heatingelement to a narrower range of about 1° C. FIG. 8D shows a temperatureprofile provided by the coffee machine.

The coffee machine can be configured to make use of a multi-inputelectronic control module, which is aware not only of the temperaturewithin the reservoir, but also of the schedule of water added to andremoved from the reservoir, the temperature of inlet water, thetemperature of the surrounding environment and the resulting temperatureof water at the portafilter (the object of control). This enables thecoffee machine to achieve further levels of temperature stability andefficiency.

FIG. 9 is a flow chart of an example method 900 for manufacturing acoffee machine, according to some example embodiments. The method 900may commence with providing an electronic control module at operation905. The electronic control module can be configured to receive brewingsettings. The brewing settings can include at least one flow set pointand at least one temperature set point. The method 900 may furtherinclude providing, at operation 910, a portafilter configured to holdcoffee. The method 900 may then continue with providing, at operation915, a group head configured to receive the portafilter. In an exampleembodiment, the group head may be provided in a form of aforward-sliding group head configured to receive the portafilter beingmoved along a track.

The method 900 may further include providing, at operation 920, at leastone water line configured to supply water.

The method 900 may further include providing at least one syringe pumpat operation 925. The at least one syringe pump may be configured topressurize the water based on predetermined criteria to attain the atleast one flow set point. The one syringe pump may be provided in a formof a plurality of redundant syringe pumps.

The method 900 may continue with providing an in-line heating element atoperation 930. The in-line heating element may be configured to controla temperature of the water according to the at least one temperature setpoint during an extraction process. The in-line heating element may belocated down the stream from the at least one syringe pump.

The method 900 may further include providing a feedback loop atoperation 935. The feedback loop may be configured to provide thetemperature to the electronic control module. The electronic controlmodule may be further configured to selectively adjust the temperaturebased on the brewing settings.

The method 900 may further include connecting, via the at least onewater line, an inlet to the syringe pump, connecting the syringe pump tothe in-line heating element, and connecting the in-line heating elementto the group head.

The method 900 may optionally include providing a pressure sensor. Thepressure sensor may be configured to sense pressure of the water. Thefeedback loop may be further configured to provide the pressure measuredby the pressure sensor to the electronic control module. The electroniccontrol module may be further configured to selectively adjust thepressure based on the brewing settings.

FIG. 10 is a schematic diagram showing a group head 1000 used in thecoffee machine, according to an example embodiment. The group head 1000may include a basket 1005 and a valve 1010. The group head 1010 can beused for larger quantities of grounds, for example, to accommodate dripbaskets that operate at atmospheric pressure. The valve 1010 may beprovided at the bottom of the basket 1005, such that dwell time could beseparately controlled. The group head 1000 may also accommodate a largerbasket, enabling the coffee machine to be used as a batch-brewer.

Thus, baristas may explore a full range of variables in a single device:flow profile, temperature profile, ground geometry and input mass, andfilter type and geometry: the device can achieve a continuum betweenespresso, drip, and cold-brew.

Additionally, conventional group heads are not height adjustable. In thecoffee machine 400, the group head can be put on an adjustable arm(e.g., on a vertical rack-and-pinion) to become height adjustablequickly and safely without compromising quality or temperaturestability. Therefore, the group head is height-adjustable to adjust fora wide range of heights.

FIG. 11 shows a user interface associated with a coffee machine. In someembodiments, the coffee machine may have an embedded touchscreen onwhich the user interface is displayed. In other embodiments, the userinterface may be shown via a mobile application associated with thecoffee machine and running on a mobile device associated with anoperator.

The operator may use the user interface 1105 and 1110 to selectparameters of a preinfusion process. The operator may also view the flowprofile and the temperature profile on the user interface 1115 and userinterface 1120, respectively. The operator may use the user interface1125 to select autostart, autolock, and autoscale options. The operatormay also use the user interface 1130 to select, change, and/or visualizea brewing profile.

The user interface may include an analog interface (e.g.,potentiometers), adjustment buttons (e.g., increase/decreasetemperature), an embedded screen, an embedded digitizer (e.g., atouchscreen), low-level interfaces, both wired (e.g., a Universal SerialBus (USB)) and wireless (e.g., Bluetooth), and so forth.

In an example embodiment of operation of the coffee machine, an operatorof the coffee machine may be executing, for example, these nine steps:removing a portafilter from a group head, drying a basket of theportafilter, placing the portafilter in a grinder, activating thegrinder, leveling grounds and tamping, placing the portafilter into thegroup head, activating the coffee machine, removing the portafilter whenthe extraction completes, and knocking the depleted coffee puck into aknockbox.

FIG. 12 illustrates an exemplary computing system 1200 that may be usedto implement embodiments described herein. The computing system 1200 canbe implemented in the contexts of an electronic control module, a mobileapplication running on a mobile device associated with the coffeemachine, or a user interface of the coffee machine. The exemplarycomputing system 1200 of FIG. 12 may include one or more processors 1210and memory 1220. Memory 1220 may store, in part, instructions and datafor execution by the one or more processors 1210. Memory 1220 can storethe executable code when the exemplary computing system 1200 is inoperation. The exemplary computing system 1200 of FIG. 12 may furtherinclude a mass storage 1230, portable storage 1240, one or more outputdevices 1250, one or more input devices 1260, a network interface 1270,and one or more peripheral devices 1280.

The components shown in FIG. 12 are depicted as being connected via asingle bus 1290. The components may be connected through one or moredata transport means. The one or more processors 1210 and memory 1220may be connected via a local microprocessor bus, and the mass storage1230, one or more peripheral devices 1280, portable storage 1240, andnetwork interface 1270 may be connected via one or more input/outputbuses.

Mass storage 1230, which may be implemented with a magnetic disk driveor an optical disk drive, is a non-volatile storage device for storingdata and instructions for use by a magnetic disk or an optical diskdrive, which in turn may be used by one or more processors 1210. Massstorage 1230 can store the system software for implementing embodimentsdescribed herein for purposes of loading that software into memory 1220.

Portable storage 1240 may operate in conjunction with a portablenon-volatile storage medium, such as a compact disk (CD) or digitalvideo disc (DVD), to input and output data and code to and from thecomputing system 1200 of FIG. 12. The system software for implementingembodiments described herein may be stored on such a portable medium andinput to the computing system 1200 via the portable storage 1240.

One or more input devices 1260 provide a portion of a user interface.The one or more input devices 1260 may include an alphanumeric keypad,such as a keyboard, for inputting alphanumeric and other information, ora pointing device, such as a mouse, a trackball, a stylus, or cursordirection keys. Additionally, the computing system 1200 as shown in FIG.12 includes one or more output devices 1250. Suitable one or more outputdevices 1250 include speakers, printers, network interfaces, andmonitors.

Network interface 1270 can be utilized to communicate with externaldevices, external computing devices, servers, and networked systems viaone or more communications networks such as one or more wired, wireless,or optical networks including, for example, the Internet, intranet, LAN,WAN, cellular phone networks (e.g., Global System for Mobilecommunications network, packet switching communications network, circuitswitching communications network), Bluetooth radio, and an IEEE802.11-based radio frequency network, among others. Network interface1270 may be a network interface card, such as an Ethernet card, opticaltransceiver, radio frequency transceiver, or any other type of devicethat can send and receive information. Other examples of such networkinterfaces may include Bluetooth®, 3G, 4G, and WiFi® radios in mobilecomputing devices as well as a USB.

One or more peripheral devices 1280 may include any type of computersupport device to add additional functionality to the computing system.The one or more peripheral devices 1280 may include a modem or a router.

The components contained in the exemplary computing system 1200 of FIG.12 are those typically found in computing systems that may be suitablefor use with embodiments described herein and are intended to representa broad category of such computer components that are well known in theart. Thus, the exemplary computing system 1200 of FIG. 12 can be apersonal computer, handheld computing device, telephone, mobilecomputing device, workstation, server, minicomputer, mainframe computer,or any other computing device. The computer can also include differentbus configurations, networked platforms, multi-processor platforms, andso forth. Various operating systems (OS) can be used including UNIX,Linux, Windows, Macintosh OS, Palm OS, and other suitable operatingsystems.

Some of the above-described functions may be composed of instructionsthat are stored on storage media (e.g., computer-readable medium). Theinstructions may be retrieved and executed by the processor. Someexamples of storage media are memory devices, tapes, disks, and thelike. The instructions are operational when executed by the processor todirect the processor to operate in accord with the example embodiments.Those skilled in the art are familiar with instructions, processor(s),and storage media.

It is noteworthy that any hardware platform suitable for performing theprocessing described herein is suitable for use with the exampleembodiments. The terms “computer-readable storage medium” and“computer-readable storage media” as used herein refer to any medium ormedia that participate in providing instructions to a central processingunit (CPU) for execution. Such media can take many forms, including, butnot limited to, non-volatile media, volatile media, and transmissionmedia. Non-volatile media include, for example, optical or magneticdisks, such as a fixed disk. Volatile media include dynamic memory, suchas RAM. Transmission media include coaxial cables, copper wire, andfiber optics, among others, including the wires that include oneembodiment of a bus. Transmission media can also take the form ofacoustic or light waves, such as those generated during radio frequencyand infrared data communications. Common forms of computer-readablemedia include, for example, a floppy disk, a flexible disk, a hard disk,magnetic tape, any other magnetic medium, a CD-read-only memory (ROM)disk, DVD, any other optical medium, any other physical medium withpatterns of marks or holes, a RAM, a PROM, an EPROM, an EEPROM, aFLASHEPROM, any other memory chip or cartridge, a carrier wave, or anyother medium from which a computer can read.

Various forms of computer-readable media may be involved in carrying oneor more sequences of one or more instructions to a CPU for execution. Abus carries the data to system RAM, from which a CPU retrieves andexecutes the instructions. The instructions received by system RAM canoptionally be stored on a fixed disk either before or after execution bya CPU.

FIG. 13 is a block diagram showing a high-level structure of a coffeemachine 1300, according to another example embodiment of the presentdisclosure. The coffee machine 1300 may include a water inlet 205, awater line 315, a reservoir 210, a pump 215, a first in-line heatingelement 1305 placed after the pump 215, a second in-line heating element1310 placed after the first in-line heating element 1305, and a brewingchamber 1360.

The coffee machine 1300 may include one or more temperature sensorsincluding a first temperature sensor 1325 placed between the pump 215and the first heating element 1305, a second temperature sensor 1330placed between the first heating element 1305 and the second in-lineheating element 1310, and a third temperature sensor 1335 placed betweenthe second in-line heating element 1310 and the brewing chamber 1360.The temperature sensors may include one or more thermocouples.

In an example embodiment, the reservoir 210 can be configured to holdwater. In some example embodiment, the reservoir 210 may include aheating element configured to preheat the water. The pump 215 may applypressure to the water to cause the water to flow through the water line315 via the first heating element 1305, the second in-line heatingelement 1310, and the brewing chamber 1360 and to cup 230. The brewingchamber 1360 may include a group head of a traditional espresso machine.For example, the brewing chamber 1360 may include a portafilterconfigured to hold coffee pack 220 and a group head configured toreceive the portafilter.

The coffee machine 1300 may further include and an ambient temperaturesensor 1365 to sense an ambient temperature. The coffee machine 1300 mayinclude one or more electronic control modules. The electronic controlmodules may include a heater controller 1340, a heater controller 1345,a pump feedback system 1355, and an electronic control module 1350. Insome embodiments, the heater controller 1340, the heater controller1345, and the pump feedback system 1355 can be integrated in theelectronic control module 1350.

The flow rate of brewing water necessary for accurately heating thewater can be then determined. In the coffee machine 400 shown in FIG. 4,the flow rate is determined and controlled directly by use of one ormore reciprocating syringe pumps 430. In contrast, the coffee machine1300 allows using pumps of other type, for example a vane pump, a rotaryvane pump, and a gear pump. The coffee machine 1300 may also allow usingtwo or more in-line heating elements, for example, the first heatingelement 1305 and the second in-line heating element 1310, tosimultaneously heat the water and measure the flow rate of the water.

In some embodiments, the first heating element 1305 can be used toperform partial heating of the water. The temperature delta between theinlet of the first heating element 1305 and the output of the firstheating element 1305 is a function of the ambient temperature, the flowrate of the water, the power provided to the first heating element 1305,and parameters determined by the characteristics of the first heatingelement 1305. The parameters can be predetermined, continuouslymonitored, and tuned as needed. Because all of these variables andparameters except the flow rate of the water are known, the flow ratecan be calculated with a predetermined accuracy.

The computed flow rate can be used as input to an algorithm (similar tothe coffee machine 400 shown in FIG. 4) to modulate the power providedto the second heating element 1310, thereby fine-tuning the temperatureof the brewing water before the water is delivered to the brewingchamber 1360. In some embodiments, the first heating element 1305 canperform about 80 percent of the heating of the water to provide a robustestimate for the water's flow rate to be used to modulate the power ofthe second heating element 1310.

FIG. 14 is a schematic 1400 showing functionalities of electroniccontrol modules of the coffee machine 1300, according to an exampleembodiment. In the FIG. 14, T_(a) is an ambient temperature and T_(d) isa desired brewing water temperature. The temperature T_(d) can be atemperature set point within the brewing settings provided to theelectronic control modules. T₁ is a temperature sensed by the firsttemperature sensor 1325 between the pump 215 and the first heatingelement 1305. T₂ is the intermediate temperature sensed by the secondtemperature sensor 1330 between the first heating element 1305 and thesecond heating element 1310. T₃ is a temperature sensed by the thirdtemperature sensor 1335 between the second heating element 1305 and thebrewing chamber 1360.

P₁ is power provided to the first heating element 1305. P₂ is powerprovided to the second heating element 1310. Φ is an estimated flowrate, and Θ is a vector of parameters that characterize the electricaland thermal characteristics of the first heating element 1305 and thesecond heating element 1310. The heater controller 1340 may calculatethe power P₁ and the flow rate Φ based on the ambient temperature T_(a),the temperature T₁, the intermediate temperature T₂, and the desiredbrewing water temperature T_(d). The heater controller 1345 maycalculate the power P₂ based on the flow rate Φ, the ambient temperatureT_(a), the intermediate temperature T₂, the temperature T₃, and thedesired brewing water temperature T_(d).

The heater controller 1345 may also receive a value of the currentpressure of the pump 215 from the pump feedback system 1355 andcalculate a desired value for the pressure based on the flow rate Φ, theambient temperature T_(a), the intermediate temperature T₂, thetemperature T₃, and the desired brewing water temperature T_(d). Theheater controller 1345 may provide the desired value for the pressure tothe pump feedback system 1355. The pump feedback system 1355 may adjustthe pressure of the pump 215 based on a desired value for the pressure.

Variables P₁, P₂, Φ, T₁, T₂ and T₃ depend on time. Specifically,variables P₁, P₂, Φ, T₁, T₂ and T₃ fluctuate during a time scale that isshorter than the brewing time of a single coffee beverage.

The electronic control module 1350 may include feedback systemsconfigured to update vector Θ of as data for P₁, P₂, Φ, T₁, T₂ and T₃are monitored and collected over the lifetime of the coffee machine 1300to account for change of the characteristics of the coffee machine overtime.

FIG. 15 is a flow chart showing an example method 1500 for brewingcoffee beverages, according to some example embodiments. The method 1500may commence in block 1505 with receiving, by one or more electroniccontrol modules, brewing settings. The brewing settings may include theat least one temperature set point.

In block 1510, the method 1500 may include supplying water by at leastone water line. In block, 1515, the method 1500 may include pressurizingthe water by at least one pump. In block 1520, the method 1500 mayinclude heating, by a first in-line heating element, the water to anintermediate temperature.

In block 1525, the method 1500 may include heating, by a second in-lineheating element, the water from the intermediate temperature to the atleast one temperature set point during an extraction process. Thedifference between an ambient temperature and the intermediatetemperature is larger than a difference between the intermediatetemperature and the at least one temperature set point. The differencebetween the ambient temperature and the intermediate temperature can beset to a predetermined percentage of a difference between the ambienttemperature and the temperature set point.

In block 1530, the method 1500 may include estimating, by the electroniccontrol modules and based partially on the intermediate temperature, aflow rate of the water through the first in-line heating element. Inblock 1535, the method 1500 may include adjusting, by the electroniccontrol modules and based partially on the estimated flow rate, powerprovided to the second in-line heating element. In block 1535, themethod 1500 may include controlling, by the electronic control modulesand based partially on the flow rate of the water through the firstin-line heating element, a pressure of the at least one pump. The pumpmay include one of the following: a syringe pump, a vane pump, a rotaryvane pump, and a gear pump.

Thus, coffee machines and methods for brewing coffee beverages aredescribed. Although embodiments have been described with reference tospecific exemplary embodiments, it will be evident that variousmodifications and changes can be made to these exemplary embodimentswithout departing from the broader spirit and scope of the presentapplication. Accordingly, the specification and drawings are to beregarded in an illustrative rather than a restrictive sense.

What is claimed is:
 1. A coffee machine comprising: at least one waterline configured to supply water; at least one pump configured topressurize the water; a first in-line heating element configured to heatthe water to an intermediate temperature; a second in-line heatingelement configured to heat the water from the intermediate temperatureto at least one temperature set point during an extraction process; andone or more electronic control modules configured to: receive brewingsettings, the brewing settings including the at least one temperatureset point; estimate, based partially on the intermediate temperature, aflow rate of the water through the first in-line heating element; andadjust, based partially on the estimated flow rate, a power provided tothe second in-line heating element.
 2. The coffee machine of claim 1,wherein a difference between an ambient temperature and the intermediatetemperature is larger than a difference between the intermediatetemperature and the at least one temperature set point.
 3. The coffeemachine of claim 1, wherein a difference between an ambient temperatureand the intermediate temperature is a predetermined percentage of adifference between the ambient temperature and the at least onetemperature set point.
 4. The coffee machine of claim 1, wherein the oneor more electronic control modules are configured to control, basedpartially on the flow rate of the water through the first in-lineheating element, a pressure of the at least one pump.
 5. The coffeemachine of claim 1, further comprising: a first temperature sensordisposed between the at least one pump and the first in-line heatingelement and configured to sense a first temperature of the water; asecond temperature sensor disposed between the first in-line heatingelement and the second in-line heating element and configured to sensethe intermediate temperature of the water; and a third temperaturesensor disposed between the second in-line heating element and a brewingchamber and configured to sense a second temperature of the water. 6.The coffee machine of claim 5, wherein the one or more electroniccontrol modules are configured to control a further power provided tothe first in-line heating element based on the following variables: anambient temperature, the first temperature of the water, theintermediate temperature of the water, the at least one temperature setpoint, and parameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element.
 7. The coffee machine of claim 5, wherein theone or more electronic control modules are configured to estimate theflow rate of water through the first in-line heating element based onthe following variables: an ambient temperature, the first temperatureof the water, the second temperature of the water, the at least onetemperature set point, and parameters concerning electricalcharacteristics and thermal characteristics of the first in-line heatingelement and the second in-line heating element.
 8. The coffee machine ofclaim 5, wherein the one or more electronic control modules areconfigured to: monitor, during a predetermined period, the followingvariables: an ambient temperature, the first temperature of the water,the intermediate temperature of the water, the second temperature of thewater, a flow rate of the water through the first in-line heatingelement; and update, based on the monitored variables, parametersconcerning electrical characteristics and thermal characteristics of thefirst in-line heating element and the second in-line heating element. 9.The coffee machine of claim 1, wherein the least one pump includes oneof the following: a syringe pump, a vane pump, a rotary vane pump, and agear pump.
 10. The coffee machine of claim 1, wherein the at least onewater line is configured to connect one or more of the following: aninlet to the at least pump; the at least one pump to the first in-lineheating element; the first in-line heating element to the first in-lineheating element; and the second heating element to a brewing chamber.11. The coffee machine of claim 10, wherein the brewing chamberincludes: a portafilter configured to hold coffee; and a group headconfigured to receive the portafilter.
 12. The coffee machine of claim1, wherein the at least one temperature set point vary during theextraction process according to the brewing settings.
 13. The coffeemachine of claim 1, wherein the brewing settings are provided by anoperator or predetermined based on a brewing profile.
 14. The coffeemachine of claim 12, wherein the brewing profile includes pre-programmedset points for preparing one or more of the following beverages:espresso, drip coffee, and cold brew.
 15. A method for brewing a coffeebeverage, the method comprising: receiving, by one or more electroniccontrol modules, brewing settings, the brewing settings including the atleast one temperature set point; supplying water by at least one waterline; pressurizing the water by at least one pump; heating, by a firstin-line heating element, the water to an intermediate temperature;heating, by a second in-line heating element, the water from theintermediate temperature to the at least one temperature set pointduring an extraction process; estimating, by the one or more electroniccontrol modules and based partially on the intermediate temperature, aflow rate of the water through the first in-line heating element; andadjusting, by the one or more electronic control modules and basedpartially on the estimated flow rate, a power provided to the secondin-line heating element.
 16. The method of claim 15, wherein adifference between an ambient temperature and the intermediatetemperature is larger than a difference between the intermediatetemperature and the at least one temperature set point.
 17. The methodof claim 15, wherein a difference between an ambient temperature and theintermediate temperature is a predetermined percentage of a differencebetween the ambient temperature and the at least one temperature setpoint.
 18. The method of claim 15, further comprising controlling, bythe one or more electronic control modules and based at least partiallyon the flow rate of the water through the first in-line heating element,a pressure of the at least one pump.
 19. The method of claim 15, whereinthe least one pump includes one of the following: a syringe pump, a vanepump, a rotary vane pump, and a gear pump.
 20. A coffee machinecomprising: a brewing chamber; at least one water line configured tosupply water; at least one pump configured to pressurize the water; afirst in-line heating element configured to heat the water to anintermediate temperature; a second in-line heating element configured toheat the water from the intermediate temperature to at least onetemperature set point during an extraction process; a first temperaturesensor disposed between the at least one pump and the first in-lineheating element and configured to sense a first temperature of thewater; a second temperature sensor disposed between the first in-lineheating element and the second in-line heating element and configured tosense the intermediate temperature of the water; a third temperaturesensor disposed between the second in-line heating element and thebrewing chamber and configured to sense a second temperature of thewater; and one or more electronic control modules configured to: receivebrewing settings, the brewing settings including the at least onetemperature set point; estimate a flow rate of the water through thefirst in-line heating element based on an ambient temperature, the firsttemperature of the water, the second temperature of the water, the atleast one temperature set point, and parameters concerning electricalcharacteristics and thermal characteristics of the first in-line heatingelement and the second in-line heating element; and adjust a powerprovided to the second in-line heating element based on the ambienttemperature, the intermediate temperature of the water, the secondtemperature of the water, the at least one temperature set point, andparameters concerning electrical characteristics and thermalcharacteristics of the first in-line heating element and the secondin-line heating element.